Pastor Bill Johnson says, "The only way we are going to be people who bring the world an encounter with God is if we are consistently encountering Him ourselves. We can only give away what we have..."
For example, (quoting from http://en.wikipedia.org/wiki/George_M%C3%BCller)
Müller prayed about everything and expected each prayer to be answered.
Once, whilst crossing the Atlantic, his ship ran into thick fog. He explained to the captain that he needed to be in Quebec by the following afternoon, but the captain said that he was slowing the ship down for safety and Müller's appointment would have to be missed. Müller asked to use the chartroom to pray for the lifting of the fog. The captain followed him down, claiming it would be a waste of time. After Müller prayed, the captain started to pray, but Müller stopped him; partly because of the captain's unbelief, but mainly because he believed the prayer had already been answered. When the two men went back to the bridge, they found the fog had lifted.
The captain became a Christian shortly afterwards.